A wire harness (a bundle of electrical wires) comprising a bundle of plural electrical wires is routed in a vehicle or the like, and plural electrical components are electrically connected to one another through the wire harness. The connection between a wire harness and an electrical component or the connection between wire harnesses is performed through connectors which are respectively provided to these parts. A covered electrical wire which is formed by covering a core wire portion (conductive portion) with an insulating material is used as this type of electrical wire. For example, a terminal is connected to an end portion of the core wire which is exposed by exfoliating a covering material from the covered electrical wire, and a connector is mounted through the terminal.
Here, electrical wires which are different in size are used for a vehicle or the like. Therefore, when different types of crimp terminals are prepared in accordance with different sizes, the types of the crimp terminals increase, so that the manufacturing process of terminals and the management of terminals under crimping work are cumbersome.
When there is no crimp terminal adaptable to an extra-fine electrical wire, it has been hitherto proposed that a shield wire is used as a dummy conductor and swaged together with a core wire portion by a crimp terminal (see JP-A-H06-084547 (Patent Document 1), for example). It has been also proposed to enlarge the application range of the outer diameter of electrical wires by improving the shape of a crimper (see JP-A-2003-173854 (Patent Document 2), for example) and to reduce the outer diameter of a core wire portion through an ultrasonic treatment and perform crimp connection to a crimp terminal (see JP-A-2011-222311 (Patent Document 3), for example).